Efficacy of handheld iontophoresis device in enhancing transdermal vitamin C delivery: A split‐face clinical trial

Background The stratum corneum of the epidermis is the principal barrier in topical drug delivery. Currently, iontophoresis is incorporated in dermatology management to increase transdermal drug delivery. Objective To evaluate the efficacy and safety of handheld iontophoresis device in enhancing transdermal vitamin C delivery. Methods This was a prospective split‐face clinical trial with a total of 24 subjects, who presented with photoaging skin. All subjects were treated with the handheld iontophoresis device on the left side of their face, twice a week for 8 weeks. Primary outcomes were the improvement in pore tightening and skin hydration. Evaluations were done at baseline, 2‐, 4‐, 6‐, and 8‐week follow‐up. Subjects' self‐improvement scores and adverse reactions were also recorded. Results Out of 24 subjects, 17 (70.8%) completed the study protocol. Pore tightening in the iontophoresis group had significant improvement at 2‐ and 8‐week follow‐up when compared to the baseline (p = 0.019 and 0.026). Skin hydration on the iontophoresis group improved significantly at 4‐week follow‐up when compared to the baseline (p = 0.024). In the iontophoresis group, an image of the skin captured using Visioscan® showed improvement of skin texture and pore tightening at 8‐week follow‐up. Majority of the subjects in the iontophoresis group scored good improvement at 2‐, 4‐, and 6‐week follow‐up (41.7%, 29.2%, and 45.8%) when compared to the baseline. No adverse reactions were recorded. Conclusion The handheld iontophoresis device is safe and can be used as an adjunctive home treatment in enhancing transdermal vitamin C delivery.